1. Field of the Invention
This invention pertains to wind generators, and more specifically to scalable wind generators used in low to high velocity winds.
2. Description of the Related Art
Wind power is widely accepted as an environmental friendly means for producing energy. Unfortunately, wind generators available today use large and expensive turbine generators mounted at a fixed position on the end of a large pole or tower. Horizontal axis wind generators (known as HAWGs) typically use two to three large, variable pitch rotors or blades connected to a horizontally aligned generator. Mounted on the pole is a yaw drive and yaw motor that turn the generator so the rotors constantly face the wind. Ideally, HAWG's should be operated in areas that experience constant, moderate winds 16 to 25 mph. When winds exceed 40 mph, the generators are rotated away from the wind and the rotors pitched to minimize lift. Brakes are used to slow down and impede rotation of the generator.
One drawback with HAWG generators is they must be stopped during high winds. Another drawback is HAWG generators are large structures that require large supporting poles or towers to hold the generator and blades in an elevated position above the ground and away from other objects. Because of their size, they are difficult to install, visually obtrusive and expensive. They are not well suited for low wind environments, densely populated areas, scenic viewing areas, or in areas where the direction of the wind varies greatly.
What is needed is a relatively low cost, scalable, horizontal axis wind generator that can be used in low to moderate wind environments, safely mounted and operated on the ground, a roof, or a pole, and that it automatically adjust to a protective configuration during moderate to high wind conditions.